Adjustable friction-grab for fishing-tools



L. E. DICKSON.

ADJUSTABLE FRICTION GRAB FOR HSHING TOOLS. APPLICA'HO'N FI'LED JULY 10,1920.

1.378341. I Patented May 24,1921.

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UNITED STATES PATENT OFFICE.

LAWRENCE E. DICKSON. OF STRAWN. TEXAS.

ADJUSTABLE FRICTION-GRAB FOR FISHING-TOOLS.

Application filed July 10, 1920.

Palo Pinto and State of Texas. have in-.

vented certain new and useful Improvements in Adjustable 'l riction-Grabs for Fishing- Tools, of which the following is a specification.

My invention relates to grabs for fishing tools in well drilling operations and more particularly to adjustable friction grabs; and the object is to provide grabs which can be easily adjusted for different sized holes or wells and which will be automatically ad justed and the grabs automatically closed on the object to be removed. Other objects and advantages will be fully explained in the following description and the invention will be more particularly pointed out in the claims.

Reference is had to the accompanying drawings which form a part of this applica-' tion.

Figure 1 is a side elevation of the grabs and the means for operating the same. Fig. 2 is a broken sectional view, illustrating the connection of the grabs with the operating drive and with the spreading and closing block. Fig. 3 is a horizontal section, taken just below the base 7, showing the connection of the spreading and closing block with the grabs. Fig. 4 is a detail view of one of the grabs.

Similar characters of reference are used to indicate the same parts throughout the several views.

The tool is provided with the usual jars 2 and 3 and a connection 1 on the jar 2 for attaching to a stem or sinker. The jar 2 has a head 11 for striking a rod or pin 6. The arms of jar 3 slide or move freely on the head 11. The arms of jar 3 may be formed or cast integral with a base 7 which is perforated for the free passage of the rod or driving pin 6. The base 7 has a trans verse slot in the lower part to receivethe upper ends of the grabs 4. The grabs 4 are thus pivotally connected to the base 7 by pivot bolts 5 so that theupper ends of the grabs 4 will swing in the slot 13. The driving pin 6 is rigid with the spreading and closing block 8. The block 8 is operatively connected with the grabs 4 by means of lateral flanges or ribs 10 which are received in T-slots or grooves 9 in the block 8. The

Specification of Letters Patent.

atented May 24. 1921.

Serial No. 395,307.

grabs i are set at different angles by placing the pins l-l in different holes 12 in the grabs so that the pins will project under the edges of the block and support the block 8 at different adjustments to spread the grabs more or less according to the size of the hole or well. The pins 14: are frangible and when the head 11 drives the pin 6 down, the pins 14 will be broken so that the block 8 can go down and close the grabs on the object to be removed. The grabs may have teeth 15 at their lower ends to aid taking hold of the object to be removed. WYhen the tool is ready to be raised. a pull on the stem will cause the head 11 to rise and engage the head 16 for pulling on the grabs at.

\Vhat I claim is.

1.. In a fishing tool provided with adjustable jars. the lower jar having a base provided with a transverse slot therein. friction grabs pivotally connected to said base in said slot and provided with lateral flanges, a driving and spreading plate having vertical slots to receive said flanges. and a pin rigid with said plate and projecting through said base to be actuated by said upper jar.

2. In a fishing tool provided with telescopic upper and lower jars. the lower jar having a base provided with a transverse slot therein. friction grabs pivotally connected to said base in said slot, each grab having an inwardly projecting web and lateral flanges on said web. a closing and spreading plate having vertical T-slots for said web and said flanges. and a pin rigid with said plate and projecting freely through said; base to be actuated by said upper ar.

3. In a fishing tool provided with upper and lower jars telescopically connected together, the lower jar having a base provided with a transverse slot therein and the upper jar having a driving head at the lower end thereof, a pair of friction grabs pi votallv connected to said base in said slot and each grab having an inwardly projecting web and lateral flanges on said web for controlling the directions of said grabs, a plate having vertical T-shaped slots to receive said webs for opening and closing said grabs. and frangible pins for supporting said plate temporarily, and means for moving said plate vertically for opening and closing said grabs.

4. In a fishing tool provided with upper and lower jars telescopically connected together, the lower jar having a base provided with a transverse slot therein, the upper jar having a driving head, a pair of friction grabs pivotally connected to said base in said slot, each grab having an inwardly projecting web and lateral flanges diagonally positioned on said web. and a closing and spreading plate having vertical slots to receive the web and flanges, and means connected to said plate to be actuated by said 10 driving head.

In testimony whereof, I set my hand, this 3rd day of July, A. D., 1920.

LAWRENCE E. DICKSON. 

